1. Field of the Invention
This invention relates in general to frequency coded signaling systems and in particular to a connect/disconnect system for a pressure/temperature gage in an oil well.
2. Description of the Prior Art
After an oil well has been drilled, a pump and pump motor must be installed to pump the oil to the surface. In order to prevent damage to the pumping equipment and the loss of oil, it is important to monitor the pressure and the temperature in the well. This has been accomplished by installing a pressure/temperature gage in the well and connecting it to a surface recorder. In a polyphase power supply system such as a three phase "Y" connected system, the gage is connected to the neutral point of the motor winding and the recorder is connected to the neutral point of the power transformer secondary with the circuit completed through the system ground. This configuration protects the gage-recorder circuit but does not protect the pump motor from a line-to-ground fault and does not allow the power supply system to be tested periodically for faults. The only prior art alternative is the use of a separate line to connect the gage and the recorder.